emul: add TRS-80 emulator

Not complete yet, but has @KEY and @DSP, enough to get prompt.

arch/z80/trs80/Makefile

@@ -3,6 +3,8 @@ TARGET = os.bin
 BASE = ../../..
 BLKPACK = $(BASE)/tools/blkpack
 STAGE = $(BASE)/cvm/stage
+EDIR = $(BASE)/emul/z80
+EMUL = $(EDIR)/trs80
 
 .PHONY: all
 all: $(TARGET) 
@@ -12,8 +14,15 @@ $(TARGET): xcomp.fs $(STAGE) blkfs
 $(BLKPACK):
 	$(MAKE) -C ../tools
 
-blkfs: $(BLKPACK)
+blkfs: blk.fs $(BLKPACK)
 	cat $(BASE)/blk.fs blk.fs | $(BLKPACK) > $@
 
 $(STAGE):
 	$(MAKE) -C $(BASE)/cvm stage
+
+$(EMUL):
+	$(MAKE) -C $(EDIR)
+
+.PHONY: emul
+emul: $(EMUL) $(TARGET)
+	$(EMUL) $(TARGET)

emul/z80/.gitignore

@@ -3,3 +3,4 @@
 /ti84
 /sms
 /rc2014
+/trs80

emul/z80/Makefile

@@ -1,9 +1,10 @@
-TARGETS = forth rc2014 sms ti84
+TARGETS = forth rc2014 sms ti84 trs80
 OBJS = emul.o z80.o
 RC2014_OBJS = $(OBJS) sio.o acia.o sdc.o rc2014_spi.o
 SMS_OBJS = $(OBJS) tms9918.o sms_vdp.o sms_ports.o sms_pad.o ps2_kbd.o sdc.o \
 	sms_spi.o
 TI84_OBJS = $(OBJS) t6a04.o ti84_kbd.o 
+TRS80_OBJS = $(OBJS)
 CDIR = ../../cvm
 STAGE = $(CDIR)/stage
 BLKFS = $(CDIR)/blkfs
@@ -23,6 +24,9 @@ sms: sms.c $(SMS_OBJS)
 ti84: ti84.c $(TI84_OBJS)
 	$(CC) ti84.c $(TI84_OBJS) -o $@ `pkg-config --cflags --libs xcb`
 
+trs80: trs80.c $(TRS80_OBJS)
+	$(CC) trs80.c $(TRS80_OBJS) -lcurses -o $@
+
 emul.o: emul.c forth.bin $(BLKFS)
 	$(CC) -DFBIN_PATH=\"`pwd`/forth.bin\" -DBLKFS_PATH=\"`pwd`/$(BLKFS)\" -c -o emul.o emul.c
 

emul/z80/emul.c

@@ -82,7 +82,7 @@ static void mem_write(int unused, uint16_t addr, uint8_t val)
     m.mem[addr] = val;
 }
 
-Machine* emul_init()
+Machine* emul_init(char *binpath, ushort binoffset)
 {
     fprintf(stderr, "Using blkfs %s\n", BLKFS_PATH);
     blkfp = fopen(BLKFS_PATH, "r+");
@@ -99,14 +99,24 @@ Machine* emul_init()
     fseek(blkfp, 0, SEEK_SET);
     // initialize memory
     memset(m.mem, 0, 0x10000);
-    FILE *bfp = fopen(FBIN_PATH, "r");
+    if (binpath == NULL) {
+        binpath = FBIN_PATH;
+    }
+    FILE *bfp = fopen(binpath, "r");
     if (!bfp) {
-        fprintf(stderr, "Can't open forth.bin\n");
+        fprintf(stderr, "Can't open %s\n", binpath);
         return NULL;
     }
-    int i = 0;
+    int i = binoffset;
     int c = getc(bfp);
     while (c != EOF) {
+#ifdef MAX_ROMSIZE
+        if (i >= MAX_ROMSIZE) {
+            fprintf(stderr, "ROM image too large.\n");
+            fclose(fp);
+            return NULL;
+        }
+#endif
         m.mem[i++] = c;
         c = getc(bfp);
     }
@@ -118,6 +128,7 @@ Machine* emul_init()
         m.iord[i] = NULL;
         m.iowr[i] = NULL;
     }
+    m.pchooks_cnt = 0;
     Z80RESET(&m.cpu);
     m.cpu.memRead = mem_read;
     m.cpu.memWrite = mem_write;
@@ -143,6 +154,12 @@ bool emul_step()
         if (m.cpu.R1.wr.IX > m.maxix) {
             m.maxix = m.cpu.R1.wr.IX;
         }
+        for (int i=0; i<m.pchooks_cnt; i++) {
+            if (m.cpu.PC == m.pchooks[i]) {
+                m.pchookfunc(&m);
+                break;
+            }
+        }
         return true;
     } else {
         return false;

emul/z80/emul.h

@@ -3,11 +3,13 @@
 #include <stdbool.h>
 #include "z80.h"
 
+#define MAX_PCHOOK_COUNT 8
+
 typedef byte (*IORD) ();
 typedef void (*IOWR) (byte data);
 typedef byte (*EXCH) (byte data);
 
-typedef struct {
+typedef struct _Machine {
     Z80Context cpu;
     byte mem[0x10000];
     // Set to non-zero to specify where ROM ends. Any memory write attempt
@@ -21,6 +23,11 @@ typedef struct {
     // NULL when IO port is unhandled.
     IORD iord[0x100];
     IOWR iowr[0x100];
+    // function to call when PC falls in one of the hooks
+    void (*pchookfunc) (struct _Machine *m);
+    // List of PC values at which we want to call pchookfunc
+    ushort pchooks[MAX_PCHOOK_COUNT];
+    byte pchooks_cnt;
 } Machine;
 
 typedef enum {
@@ -29,7 +36,7 @@ typedef enum {
     TRI_HIGHZ
 } Tristate;
 
-Machine* emul_init();
+Machine* emul_init(char *binpath, ushort binoffset);
 void emul_deinit();
 bool emul_step();
 bool emul_steps(unsigned int steps);

emul/z80/forth.c

@@ -76,7 +76,7 @@ static void iowr_sety(uint8_t val)
 
 int main(int argc, char *argv[])
 {
-    Machine *m = emul_init();
+    Machine *m = emul_init(NULL, 0);
     if (m == NULL) {
         return 1;
     }

emul/z80/rc2014.c

@@ -11,6 +11,7 @@
 #include <stdio.h>
 #include <unistd.h>
 #include <termios.h>
+#define MAX_ROMSIZE 0x2000
 #include "emul.h"
 #include "acia.h"
 #include "sio.h"
@@ -24,7 +25,6 @@
 #define SIO_ADATA_PORT 0x81
 #define SDC_CTL 0x05
 #define SDC_SPI 0x04
-#define MAX_ROMSIZE 0x2000
 
 bool use_sio = false;
 static ACIA acia;
@@ -123,7 +123,7 @@ static void _write(uint8_t val)
 
 static void usage()
 {
-    fprintf(stderr, "Usage: ./classic [-s] [-c sdcard.img] /path/to/rom\n");
+    fprintf(stderr, "Usage: ./rc2014 [-s] [-c sdcard.img] /path/to/rom\n");
 }
 
 int main(int argc, char *argv[])
@@ -159,23 +159,9 @@ int main(int argc, char *argv[])
         usage();
         return 1;
     }
-    fp = fopen(argv[optind], "r");
+    Machine *m = emul_init(argv[optind], 0);
-    if (fp == NULL) {
+    if (m == NULL) return 1;
-        fprintf(stderr, "Can't open %s\n", argv[1]);
-        return 1;
-    }
-    Machine *m = emul_init();
     m->ramstart = RAMSTART;
-    int i = 0;
-    int c;
-    while ((c = fgetc(fp)) != EOF && i < MAX_ROMSIZE) {
-        m->mem[i++] = c & 0xff;
-    }
-    pclose(fp);
-    if (i == MAX_ROMSIZE) {
-        fprintf(stderr, "ROM image too large.\n");
-        return 1;
-    }
     bool tty = isatty(fileno(stdin));
     struct termios term, saved_term;
     if (tty) {

emul/z80/sms.c

@@ -7,6 +7,7 @@
 #define XK_MISCELLANY
 #include <X11/keysymdef.h>
 
+#define MAX_ROMSIZE 0x8000
 #include "emul.h"
 #include "sms_vdp.h"
 #include "sms_ports.h"
@@ -23,7 +24,6 @@
 #define PORTS_IO2_PORT 0xdd
 #define SDC_CTL 0x05
 #define SDC_SPI 0x04
-#define MAX_ROMSIZE 0x8000
 
 static xcb_connection_t    *conn;
 static xcb_screen_t        *screen;
@@ -334,18 +334,9 @@ int main(int argc, char *argv[])
         fprintf(stderr, "Can't open %s\n", argv[1]);
         return 1;
     }
-    m = emul_init();
+    m = emul_init(argv[optind], 0);
+    if (m == NULL) return 1;
     m->ramstart = RAMSTART;
-    int i = 0;
-    int c;
-    while ((c = fgetc(fp)) != EOF && i < MAX_ROMSIZE) {
-        m->mem[i++] = c & 0xff;
-    }
-    pclose(fp);
-    if (c != EOF) {
-        fprintf(stderr, "ROM image too large.\n");
-        return 1;
-    }
     if (use_kbd) {
         ports.portA_rd = iord_kbd;
     } else {

emul/z80/ti84.c

@@ -14,6 +14,7 @@
 #define XK_MISCELLANY
 #include <X11/keysymdef.h>
 
+#define MAX_ROMSIZE 0x4000
 #include "emul.h"
 #include "t6a04.h"
 #include "ti84_kbd.h"
@@ -23,7 +24,6 @@
 #define INTERRUPT_PORT 0x03
 #define LCD_CMD_PORT 0x10
 #define LCD_DATA_PORT 0x11
-#define MAX_ROMSIZE 0x4000
 
 static xcb_connection_t    *conn;
 static xcb_screen_t        *screen;
@@ -288,23 +288,9 @@ int main(int argc, char *argv[])
         fprintf(stderr, "Usage: ./ti84 /path/to/rom\n");
         return 1;
     }
-    FILE *fp = fopen(argv[1], "r");
+    m = emul_init(argv[1], 0);
-    if (fp == NULL) {
+    if (m == NULL) return 1;
-        fprintf(stderr, "Can't open %s\n", argv[1]);
-        return 1;
-    }
-    m = emul_init();
     m->ramstart = RAMSTART;
-    int i = 0;
-    int c;
-    while ((c = fgetc(fp)) != EOF && i < MAX_ROMSIZE) {
-        m->mem[i++] = c & 0xff;
-    }
-    pclose(fp);
-    if (i == MAX_ROMSIZE) {
-        fprintf(stderr, "ROM image too large.\n");
-        return 1;
-    }
     t6a04_init(&lcd);
     kbd_init(&kbd);
     lcd_changed = false;

emul/z80/trs80.c

@@ -0,0 +1,103 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <curses.h>
+#include <termios.h>
+#include "emul.h"
+
+#define WCOLS 80
+#define WLINES 24
+#define RAMSTART 0
+#define BINSTART 0x3000
+
+WINDOW *bw, *dw, *w;
+
+void debug_panel()
+{
+    char buf[30];
+    emul_debugstr(buf);
+    mvwaddnstr(dw, 0, 0, buf, 30);
+    wrefresh(dw);
+}
+
+static void pchookfunc(Machine *m)
+{
+    byte val;
+    switch (m->cpu.R1.br.A) {
+    case 0x01: // @KEY
+        debug_panel();
+        m->cpu.R1.br.A = wgetch(w);
+        break;
+    case 0x02: // @DSP
+        val = m->cpu.R1.br.C;
+        if (val == '\r') {
+            val = '\n';
+        }
+        if (val >= 0x20 || val == '\n') {
+            wechochar(w, val);
+        } else if (val == 0x08) {
+            int y, x; getyx(w, y, x);
+            wmove(w, y, x-1);
+        }
+        break;
+    case 0x03: // @GET
+        break;
+    case 0x04: // @PUT
+        break;
+    case 0x0f: // @VDCTL
+        wmove(w, m->cpu.R1.br.H, m->cpu.R1.br.L);
+        break;
+    case 0x16: // @EXIT
+        break;
+    case 0x1a: // @ERROR
+        break;
+    case 0x28: // @DCSTAT
+        break;
+    case 0x31: // @RDSEC
+        break;
+    case 0x35: // @WRSEC
+        break;
+    default:
+        fprintf(stderr, "Unhandled RST28: %x\n", m->cpu.R1.br.A);
+    }
+}
+
+static void usage()
+{
+    fprintf(stderr, "Usage: ./trs80 /path/to/rom\n");
+}
+
+int main(int argc, char *argv[])
+{
+    if (argc < 2) {
+        usage();
+        return 1;
+    }
+    Machine *m = emul_init(argv[1], BINSTART);
+    if (m == NULL) return 1;
+    m->ramstart = RAMSTART;
+    m->pchookfunc = pchookfunc;
+    m->pchooks_cnt = 1;
+    m->pchooks[0] = 0x28; // RST 28
+    // Place a RET at 0x28 so that it properly returns after pchookfunc().
+    m->mem[0x28] = 0xc9; // RET
+    m->cpu.PC = BINSTART;
+    initscr(); cbreak(); noecho(); nl(); clear();
+    // border window
+    bw = newwin(WLINES+2, WCOLS+2, 0, 0);
+    wborder(bw, 0, 0, 0, 0, 0, 0, 0, 0);
+    wrefresh(bw);
+    // debug panel
+    dw = newwin(1, 30, LINES-1, COLS-30);
+    w = newwin(WLINES, WCOLS, 1, 1);
+    scrollok(w, 1);
+    while (emul_steps(1000)) {
+        debug_panel();
+    }
+    nocbreak(); echo(); delwin(w); delwin(bw); delwin(dw); endwin();
+    printf("\nDone!\n");
+    emul_printdebug();
+    printf("PC: %x\n", m->cpu.PC);
+    emul_deinit();
+    return 0;
+}